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Evaluation of Treatment for Removing Giardia Cysts
Author(s) -
Ongerth Jerry E.
Publication year - 1990
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1990.tb06982.x
Subject(s) - backwashing , turbidity , filtration (mathematics) , water treatment , giardia , cyst , environmental science , effluent , filter (signal processing) , environmental engineering , pulp and paper industry , biology , mathematics , medicine , microbiology and biotechnology , surgery , ecology , geology , engineering , geomorphology , inlet , statistics , electrical engineering
The removal of Giardia cysts by three small (0.01‐ to 0.57‐mgd) treatment plants—one with conventional filtration, one with in‐line filtration, and one with diatomaceous earth filtration—was studied. Turbidity and cyst removals for each were compared with those of parallel pilot filters (1 gpm) seeded with Giardia cysts and with and without optimization of chemical treatment. Cyst removal efficiencies ranged from about 40 to 99 percent. Design and operating deficiencies likely contributed to the observed treatment performances. Major deficiencies included lack of or poor optimization of chemical treatment, on‐off cycles of filters without backwashing, absence of operator control of backwashing, and no filtering to waste.